I found it very difficult to change having been on android since 2009.

The lack of a back gesture is the number one annoyance for me as there are times you are not really sure how to go back one page or UI element. Every app does it slightly differently and it impacts one handed usefulness and accessibility.

Secondly, the notifications are much better on Android as they are more logically grouped and easier to manage and see at a glance. It's more like a notification pile on iOS with badges to show what's come in.

Third, media storage and the player do not feel user friendly. It's hard to access files between a computer and iPhone and the photos app does not have some basic features like playback speed or auto loop.

However, iOS definitely wins in terms of ecosystem and app quality. Basic apps feel better optimized and smoother. It's different but you'll get used to doing things "the Apple way". I hope they finally upgrade some quality of life features in iOS 17 but I wouldn't have my hopes too far up.